Fire Capt. David Atkin of the San Ramon Valley Fire Protection District said crews were called to the building around 1:15 p.m. on reports of water gushing several feet up into the air.
Atkin said a work crew had utilized a fire department connection to shut down the water flow to the sprinkler system in order to perform some routine maintenance. But apparently the department's shutoff valve was not working and when the crew loosened the valve leading into the building, the water pressure forced the top off and water shot up several feet. After only a few minutes water was six to eight inches deep outside the building and was slowly flooding the ground floor offices.
Atkin said crews attempted closing off the valve but it remained inoperative so they were forced to go to a secondary valve location on San Ramon Valley Boulevard in order to cut off the water feed.
Once the water was controlled, crews began taking out items that may have been damaged and cleaning up several inches of water still flowing in the offices.
No word on damages has been issued by the fire department, and investigators are working to determine why the sprinkler valve malfunctioned.